PURPOSE: To obtain the phase shift mask for which an inorg. material having good resistance is used as the phase shift material by forming a phase shift material pattern constituted of the inorg. material wider than a light shielding part on the light shielding part and forming this wide part as a phase shift part.

CONSTITUTION: Quartz is used as a light transparent substrate 1 and a film is formed of Cr as the light shielding material thereon to provide the light shielding material layer 10a. A film is then formed of ITO which is the inorg. material thereon to provide the phase shift material layer 11. A resist film for patterning is thereafter formed and is formed with a resist pattern 2. The layer 11a consisting of the ITO is anisotropically etched by using Cl2 as a gaseous system with this pattern as a mask; in succession, the material layer 10a is anisotropically etched by the same gaseous system. Both layers 11a, 10a are patterned by one stage to obtain the patterns 11b, 10b and thereafter, the pattern 2 is removed. The side parts of the pattern 10b are thereafter wet etched to recess the side parts of the pattern 10b (10c). The part wider than the light shielding part 10 forms the phase shift part 11 in this way and the phase shift mask formed of the inorg. material in the pattern 11b is obtd.